Dr. John Strahler's addition to the Mass Spectrometry Facility staff brings high resolution two dimensional gel electrophoresis technology into this group. To interface the gel electrophoresis technology with MALDI technology, we are continuing to develop our abilities to obtain MALDI spectra "directly" from membranes such as Zetabind. A membrane holder has been constructed, which can be placed into the MALDI ion source. The holder provides an option for placing an equipotential grid across the surface of the membrane, to avoid degraded mass spectral performance that has been observed when membrane substrates are used, presumably due to charging of this insulating material. The first membrane holder developed allows for "1 dimensional" membranes to be subjected to MALDI-MS analysis. When optimized, a stage will be constructed to carry electroblotted membranes from larger area 2-D gels. Membranes will continue to serve a variety of purposes in the lab, as well as their obvious role in the electroblotting of proteins from gels. Samples can be applied directly to membranes, and can be washed to remove contaminants such as salts and detergents. Also, samples can be digested or chemically modified directly on membranes.